Study of airborne radioactivity near to the high water mark at Drigg Point

Measurements are reported on radionuclides collected at Drigg Point using muslin screen aerosol collectors arranged along two transects leading inland from the high water mark for ˜300m. The results of seven long-term exposures, taken over periods of 1.0–8.2 weeks, and three short-term exposures, taken over 1.5–2.2 h at different states of the tide, are presented. A determination of γ-ray emitting radionuclides collected by the screens was used to determine the relative concentrations of radioisotopes in the air as a function of distance inland. Average wind speeds were calculated for each exposure using data obtained from the nearby Eskmeals weather station. Reductions in the radionuclide concentrations vs distance inland calculated using the SALT model of Nelis et al. (Atmos. Environ. 1994, 28, 3213–23) are shown to reproduce the data reasonably well. It is concluded that the results are useful for testing models of the radionuclide dispersion and deposition.